Effects of endurance training on heart rate and blood pressure variability

PURPOSE: To study the influences of a 1-year controlled, randomized endurance exercise training period on heart rate (HR) and blood pressure variability in a representative sample of Finnish men in their late middle age. METHODS AND RESULTS: Subjects were 140 sedentary men aged 53-63 years. The men were randomized into two identical groups: an intervention (EX) and a reference (CO) group. One hundred and twelve of them remained in the final analysis (EX: n=59, CO: n=53). EX trained for 30-60 min three to five times a week with the intensity of 40-60% of maximal oxygen consumption. In EX, 1 year of regular exercise training increased oxygen consumption at respiratory compensation threshold by 11% (P < or = 0.001) in a maximal cardiorespiratory test. Total power and very low frequency power of R-R interval variability (ms2) tended to increase in the EX group by 26 and 42% and to decrease in the CO group by 13 and 10% (interaction P<0.05 and P<0.01), respectively. There were no significant changes in blood pressure variability. CONCLUSION: Regular low- to moderate-intensity exercise training could retard the declining tendency in cardiac autonomic nervous function in older men during 1 year.